Sharpening implement



Feb. 27, 1945. E. PRoBsT' SHARPENING IMPLEMENT -Filed Oct. 23, 1943 INVENTOR Z'm meE Prom,

ATTORNEY.

Patented Feb. 27, 1945 NITE STATES PATENT ori ice SHARPENING IMPLEMENT Emmet Probst, Mountain View, N. J. Application October '23, 1943, Serial No. 507,385-

6 Claims. (01. 51- 214) This invention relates to tool-sharpening devices. The object is to' provide an efficient implement of this class adapted to sharpen various tools and which, in particular, can be manufactured at little expense and therefore purchased at small cost, it comprisingbut two parts, the actual sharpening or abrading element and a simple shell or case containing said element. Preferably the case is to be so formed that whereas said element is, at least normally, inseparable from it, said element may change or be made to change its position therein so as to disperse the wear which said element undergoes when-in use.

As will appear, the sharpening element is -'a body having opposite substantially parallel plane surfaces, one of which at least is its abrading surface, though said body as-a whole may-be composed of abrasive substance; in the preferred form said body is circular in plan. The case or shell is formed from a simple blank of stiff sheet material, as metal, having suitable apertures, by bending the blank so as to leave only limitedpor. -tions of the perimeter of said body protruding at said apertures when it is assembled with the case, thus to confine the body therein, and also so-that the case provides a guiding slot, reaching to said plane abrading surface, for receiving the tool be ing sharpened.

In the drawing,

Fig. 1 is a plan of said blank;

Figs. 2 and 3 are respectively a \side eleva tion, viewed transversely of the tool-guiding slot, and a plan of the device;

Fig. 4 is a side elevation of said device, viewed lengthwise of the slot, the blade being sharpened appearing in section;

Figs. 5 and 6 are side elevations of modified forms of the device, with the blade being sharpened appearing respectively in section and end elevation; and

Fig. 7 is an enlarged fragmentary. section of what appears in Fig. 6.

Describing the device as per the examples shown:

The abrading or sharpening element l is a fiat circular block or cylinder composed whollyof abrading substance, one of whose lane surfaces, as la, is to serve as its sharpening surface.

The shell or case 2 is formed from the generally oblong blank 2a of, say, stifi sheet metal having its corners preferably beveled or rounded and having a pair of spaced rectangular apertures 3 of the same dimensions nd spaced equally from the end edges of the blank with their four sides parallel with the respective four edges ofthe blank, the dimension of each transversely of the blank eing somewhat greater than thethickness of the element l. The blank is to be rightangularly' bent in one direction on the .four

dotted lines .4 coincident with end edges of. the

blank and also right-angularly bent inithe opposite direction on'lines 5. 'In the assembledstate of element 1 and the case said element is con.-

"tained in thecase with diametrically opposite peripheral portions thereof protruding from "the apertures, wherefore said element is confinediin .the case, having one plane face'th'ereof exposed by the slot which exists between the lips 6 formed by bending the blank on 1ines'5. The arrangement is such that element I has somefr'eedom to rotate in the case so long as its more. or lessbe a lawnmower blade; Holding the sharpening device in his hand, with the blade entered in the' slot between the lips 6, the operator moves the device back and forth lengthwise of the blade. He

may rotate the element 2 from time to time to avoid grooving the same, such rotation also of course occurring in casual handling of the de- VICE. I

In the form shown in Fig. 5 the device is the same as before excepting that one of the lips to of the case 8' is inclined'to overhang the portion of surface Ia'of said'element exposed bytheslot, the other lip being here omitted. The incline of lip 8a adapts the device to the sharpening of the beveled edge of a tool 9, such as a scissors blade.

In Figs. 6 and '7 both lips H and I2 of the case H) appear, with lip ll inclined to overhang the slot but in sharp acute-angular relation to surface la and lip 12 normally parallel with said surface. In this form the device is used for sharpening a blade l3, as of a knife, having a quite acute-angular cross-section. Under the pressure applied to the blade lip l2, incident to elasticity in the case, may yield downwardly, as shown dotted in Fig. '7, to position the blade at the proper angle to said surface. The lip ll serves in this case as a guard.

According to my invention walls of the four going to form the case and resulting from bending the blank in the examples set forth and so as to leave-one such wall slotted, as between the lips 8, serve to confine the abrading element within the case while leaving it free for rotation around an axis perpendicular to its planiform surfaces, thus distinguishing from previous devices of this class in which a pin or the like was included as a part of the case to serve as a bearing for said element and confine it in the case. With one or both of the apertures 3 present the operator during the sharpening and in gripping the device can limit or controllably rotate said element; and with one or both of said apertures present and the spacing of the walls in which they are formed less than the diameter of said (substantially circular) element the confining of said element within the case is specifically an incident of a segment of said element being received by at least one such aperture.

Having thus fully described my invention, what I claim is:

l. A tool-sharpening device comprising in combination, with an abrading element havihg substantially planiform and substantially parallel surfaces facing away from each other and one of which is an abrading surface, a case of stiff sheet material containing said element and having two walls closely facing said surfaces, respectively, one of which has a slot exposing said abrading surface, and two other walls connecting the first two walls and having said element between them, said element being rotative in the case around an axis penetrating the first two wall and, being free to shift transversely of said axis and confined by walls of-the case against displacement :2

from within the case.

2. A tool-sharpening device comprising in combination, with an abrading element having substantially planiform and substantially parallel surfaces facing away from each other and one of which is an abrading surface, a case of stiff sheet material containing said element and having two walls closely facing said surfaces, respectively, one of which has a slot exposing said abrading surface, and two other walls connecting the first two walls and having said element between them, said element being rotative in the case around an axis penetrating the first two walls and being free to shift transversely of said axis and confined by the second two walls against displacement from within the case.

3. A tool-sharpening device comprising in combination, with an abrading element having substantially planiform and substantially parallel surfaces facing away from each other and one of which is an abrading surface, a case of stiff sheet material containing said element and having two walls closely facing said surfaces, respectively, one of which has a slot exposing said abrading surface, and two other walls connecting the first two walls and having said element between them, said element being rotative in the case around an axis penetrating the first two walls and being free to shift transversely of said axis and confined by walls of the case against displacement from within the case, and said element being substantially circular viewed lengthwise of said axis and one of the second two walls having an aperture exposing the periphery of said element.

4. A tool-sharpening device comprising in combination, with an abrading element having substantially planiform and substantially parallel surfaces facing away from each other and one of which is an abrading surface, a case of stiff sheet material containing said element and having two walls closely facing said surfaces, respectively, one of which has a slot exposing said abrading surface, and two other walls connecting the first two walls and having said element between them, said element being rotative in the case around an axis penetrating the first two walls and being substantially circular viewed lengthwise of said axis and the second two walls being spaced apart a distance less than the diameter of said element and having apertures receiving segments of the periphery thereof.

5. The device set forth in claim 1 characterized by said case being formed from a substantially rectangular blank of stiff sheet material bent around said element on lines parallel with two of opposed edges of the blank and so as to leave said edges spaced apart and providing between them said slot.

6. A tool-sharpening device comprising, in combination, an abradingelement having a circular periphery in the plane of its maximum circular area and its exterior surface substantially wholly abrasive, a case of stiff sheet material extending around said element in close relation thereto and in which said element is rotative around the axis of its said periphery and said case having wall portions spaced apart less than the diameter of said periphery and formed with apertures into which portions of said periphery project and by which the latter portions are exposed, said aper- 

